Similar to gravity units but include copper coil heat exchanger which can be fed water main pressure to pre- heat water to tank temperature. Especially usefull for on-demand water heaters that can except pre-heated water. No circulator pump required.
Freight shipment pricing calculated after order all depends on where you are located.
When shipment is shipped please add an $75.00 for 5 extra tubes in case of breakage during shipment.